Last year 10 per cent of its upper sixth received offers from Oxbridge

The school is set on a 120-acre estate in the village of Steep, near Petersfield. The grounds boast woodland and a nature reserve as well as a theatre

Today it educates some 462 pupils, housing 70 per cent of them in dormitories. It has retained its liberal leanings and relaxed attitude to discipline

Boarding fees are £30,000 a year – equal to the top 15 most expensive UK schools

Daniel Day-Lewis, Kirsty Allsopp, Viscount Linley, actress Minnie Driver, actor Simon Cadell and Sophie Dahl all attended Bedales. A teacher, who wished to remain anonymous, said the school was in crisis.

In a letter to parents, the teacher wrote: ‘As parents you need to ask “who has lost their job” over the scandal that occurred when 13-year-old children (it could be your child) took drugs, drunk and had sex on the school premises and in school time.

‘The total lack of care is shocking and you should be asking questions about the safety of your children and why certain members of staff are constantly protected.’

The incident, which took place on June 29, followed the recent expulsion of two boys, thought to be 14, for persistent misbehaviour.

He said he was questioning his decision to educate his children at Bedales. ‘I sent my daughter to Dunhurst because of its good reputation. It seemed like a perfect place for her to establish herself. I thought it was a safe environment. But I don’t want to be spending £30,000 a year sending my child to a school that allows this sort of nonsense to go on.’

Bedales, with a roll of 462 pupils aged 13 to 18, three-quarters of whom are boarders, has been co-educational since the late 1800s.

The Good Schools Guide says it is ‘still good for “individuals”, articulate nonconformists and people who admire such qualities’. Headmaster Keith Budge outlined the incidents in a letter to year nine parents with children aged 13 to 14.

He said: ‘On the penultimate Wednesday of term, four Block Three students were involved in a series of disciplinary incidents, starting with one of them stealing a bottle of whisky from Waitrose and ending up on their return from Petersfield in the sand quarry.

‘Following a formal investigation of these incidents and further questioning at the resulting disciplinary hearings, I asked three of these students – two boys and a girl – to leave the school. One boy went for theft, the other two for sexual misconduct.’

Scandal: Three pupils were expelled for incidents during an end of term party

He added: ‘This recent incident has highlighted misbehaviour of a small group of students, especially with regard to sexual behaviour.’

He also alluded to problems with internet bullying at the school saying he was aware of ‘the dangers of allowing teenagers unchecked access to social media’.

Last night a spokesman declined to confirm if the school had contacted Hampshire Police but said: ‘We have consulted with the relevant authorities.’

He added: ‘I can confirm there was a disciplinary incident in the penultimate week of term.

‘This robust action indicates how seriously the school takes the upholding of high standards of student behaviour.

‘In the interests of the children concerned and their families it would be inappropriate to comment further.’